Laser beam machining system and laser beam machining method using the same

ABSTRACT

The object of this invention is to provide a laser beam machining system and a laser beam machining method, wherein the working environment for the laser beam machining in the safety cabin is not impaired, and carrying out of the machined work can be performed without causing a shift of the machined work on the machining table, and also, without the laser beam machining being suspended, thereby enabling improvement in the productivity. At least one carriage of two, first and second carriages ( 11 ), ( 19 ) placed in a safety cabin ( 29 ) is moved back and forth above a machining table, and a laser machining head provided in that carriage is moved right and left, to thereby perform laser beam machining with respect to a work (W) on a machining table ( 7  or  9 ). The second carriage is moved back and forth above the machining table ( 7  or  9 ), so that a holding device ( 25 ) provided in the second carriage is moved right and left, to thereby hold and carry the machined work (W). Features of double carriages ( 11, 19 ) in the safety cabin ( 29 ) can be fully utilized, enabling improvement in the productivity.

TECHNICAL FIELD

The present invention relates to a laser beam machining system and alaser beam machining method using this laser beam machining system.

BACKGROUND ART

Conventionally, at the time of laser beam machining by a laser beammachine 101, it is necessary to cover the whole laser beam machine 101including a machining table 103, on which a work W is placed, with asafety cabin 105, as shown in FIG. 4, from a viewpoint of safety of theoperator and working environment. Especially, in EC countries, in orderto acquire the “CE mark”, the measure for covering the laser beammachine with the safety cabin 105 is necessary and indispensable. It isconsidered that the similar tendency will also dominate the Japanesemarket.

Generally, in the laser beam machine 101 in which a carriage 109 forsupporting the laser machining head 107 is single in FIG. 4, aseparately disposed manipulator 111 has been used to unload a machinedwork W (product G in FIG. 4). For example, the manipulator 111 is ableto travel freely in the back and forth direction (X-axis direction), andthe manipulator 111 has a holding device 113 for holding the work W,provided thereon so as to be able to go freely up and down and to movefreely right and left. As a result, the holding device 113 is disposedso as to be moved and positioned freely back and forth (X axis), rightand left (Y axis), and up and down (Z axis).

In the laser beam machine 101 capable of carrying in and out the work W,as in the case where a shuttle table 115 is provided as a machiningtable 103 for placing the work W thereon, the machined work W and askeleton are carried out at the same time while a new work W ismachined.

When the above-described laser beam machine 101 is completely coveredwith the safety cabin 105, it is necessary to open or close a door 117disposed on the side of the safety cabin, after the laser beam machininghas been suspended, in view of the purpose of the safety cabin 105.

In the conventional laser beam machining system, needless to say, safetyand being convenient are two sides of the system, and performing thelaser beam machining with the laser beam machine 101 covered with thesafety cabin 105 has many problems in speed-up and efficiencyimprovement. Moreover, the safety cabin 105 becomes a cause of a delayin labor saving from a viewpoint of the productivity and care withrespect to a defect of the work W.

Moreover, in the case of the laser beam machine 101 comprising theshuttle table 115, there is a problem in that when the machined work Wcarried out on the shuttle table 115 is picked up by the manipulator 111(takeout loader or unloader) in order to take it out from the skeleton,the work W is shifted, thereby finally, it may not be taken out.

On the other hand, there is a problem in that after the cutting processof the work W by means of the laser beam machining has been finished,when the machined work W is picked up by the manipulator 111, the work Wmay not be taken out due to inclination, depending on the shape of thework W.

Therefore, as shown in FIG. 6, the laser beam machining is suspended inthe middle of the cutting process of the work W, slightly leaving theuncut portion N (unmachined portion), shown by a two-dot chain line, andthe side of the cut portion C of the work W is picked up in thedirection shown by an arrow, as shown in FIG. 7, by the holding device113 of the manipulator 111, and thereafter, the remaining uncut portionN is cut by the laser beam machining. The machined work W is taken outby the manipulator 111, and accumulated in the product accumulationarea, as shown in FIG. 4, and the accumulated machined works W (productsG) are taken out by a forklift, and assorted manually.

In this case, when the work W is picked up by the manipulator 111described above, in the middle of the cutting process and after thecutting process of the work, as shown in FIG. 5, it is necessary tosuspend the laser beam machining to open and close the door 117 of thesafety cabin 105. Accordingly, in other words, the time required foropening and closing the door 117 of the safety cabin 105 is the timethat does not contribute to the productivity, since the laser beammachining cannot be performed during that time.

In detail, the above-described series of steps comprise steps of: (1)performing laser beam machining with respect to a work W halfway, (2)opening the door 117 of the safety cabin 105 (3) letting the manipulator111 enter into the safety cabin 105 from the door 117, (4) closing thedoor 117 of the safety cabin 105, (5) picking up the work W by themanipulator 111, (6) performing laser beam machining with respect to theremaining portion of the work W, (7) taking out the machined work W bythe manipulator 111, (8) opening the door 117 of the safety cabin 105,(9) moving the manipulator 111 from the door to the outside of thesafety cabin 105, and (10) closing the door 117 of the safety cabin 105.

Incidentally, the whole processing time required for cutting one work Wby the laser beam machining in the above manner was, for example, 30seconds. The breakdown was such that pure laser beam machining time inthe steps (1) and (6) was for example 12 seconds, and the pick-up timeof the work W and the opening and closing time of the door 117 in othersteps (2) to (5) and (7) to (10) were for example 18 seconds.

As described above, there is a problem in that the productivitydecreases, since the time for suspending the laser beam machiningbecomes long, as the laser beam machining is performed within the safetycabin 105.

DISCLOSURE OF INVENTION

The present invention has been achieved in order to solve the aboveproblems, and it therefore is the object of the present invention toprovide a laser beam machining system and a laser beam machining method,using this laser beam machining system, wherein the working environmentfor the laser beam machining in the safety cabin is not impaired, andcarrying out of the machined work can be performed without causing ashift of the machined work on the machining table, and also, without thelaser beam machining being suspended, thereby enabling improvement inthe productivity.

In order to achieve the above object, a first aspect of the presentinvention provides the laser beam machining system, wherein a machiningarea and an accumulation area adjacent to the machining area areprovided in a safety cabin, a machining table is disposed in themachining area, and first and second carriages disposed on the oppositesides of the machining area are provided movably back and forth, locatedabove the machining table, a laser machining head movable in the leftand right direction is disposed in the first carriage, and a machininghead movable in the left and right direction and a holding device forholding a work on the machining table are disposed in the secondcarriage.

Accordingly, the feature of double carriages in the safety cabin can befully utilized, and even in the middle of cutting a work by the lasermachining head provided in the first carriage, the work is picked up bythe holding device provided in the second carriage, and the machinedwork is carried out to the accumulation area in the safety cabin. As aresult, the working environment for the laser beam machining is notimpaired, and carrying out of the machined work can be performed withoutcausing a shift of the machined work on the machining table, and also,without the laser beam machining being suspended, thereby enablingimprovement in the productivity.

A second aspect of the present invention provides the laser beammachining system according to the first aspect, wherein the machininghead in the second carriage comprises at least one of a laser machininghead, a marking head, or a drilling head.

Accordingly, with the second carriage, not only carrying out of the workby means of the holding device, but also other machining can beperformed, such as laser beam machining, marking or drilling.

A third aspect of the present invention provides the laser beammachining system according to the first or second aspect, wherein anopening for carrying out a work is provided on the side of the safetycabin, and a work transport means capable of carrying a work from insideof the safety cabin to the outside through the opening is provided inthe accumulation area.

Therefore, the machined work accumulated in the safety cabin can becarried out easily and quickly by the work transport means through theopening. Carrying out at this time is performed during a set-up change,and does not affect the productivity.

A fourth aspect of the present invention provides the laser beammachining system according to the third aspect, wherein a freelyopenable door or an air curtain is arranged in the opening.

Therefore, by providing the freely openable door in the opening, laserbeam machining can be performed without impairing the workingenvironment in the safety cabin. Moreover, by providing the air curtain,continuous carrying out of the work is possible without impairing theworking environment in the safety cabin.

A fifth aspect of the present invention provides the laser beammachining system, wherein at least one carriage is provided movably backand forth, located above a machining table in a safety cabin whose upperportion is released, a laser machining head movable right and left isdisposed in the at least one carriage, and a takeout loader is provided,which comprises a holding device for holding a work on the machiningtable from the release portion on the upper part of the safety cabin, soas to be movable vertically and substantially horizontally above thesafety cabin.

Therefore, since carrying out of the work is performed from the releaseportion on the upper part of the safety cabin by means of the holdingdevice in the takeout loader, the working environment for the laser beammachining is not impaired, and carrying out of the machined work can beperformed without causing a shift of the machined work on the machiningtable, and also, without the laser beam machining being suspended,thereby enabling improvement in the productivity.

Moreover, it is also effective in the case of using a single carriage,and it is possible to carry out the works to the outside of the safetycabin all at once, without accumulating the works in the safety cabin.In the case of double carriages, it is possible to be involved in othermachining such as laser beam machining, marking or drilling with theother second carriage.

A sixth aspect of the present invention provides the laser beammachining system according to either one of the first to sixth aspects,wherein the machining table is a shuttle table.

Therefore, the time for carrying out the machined work to the outside ofthe safety cabin is reduced. As a result, this shuttle table can beeffectively utilized, without delaying the time for a set-up change.

A seventh aspect of the present invention provides the laser beammachining method, wherein at least one of first and second carriagesplaced in a safety cabin is moved in the back and forth direction abovea machining table, while a laser machining head provided in the at leastone carriage is moved in the left and right direction to thereby performlaser beam machining on a work on the machining table, and the secondcarriage is moved in the back and forth direction above the machiningtable, while a holding device provided in the second carriage is movedin the left and right direction to hold the machined work to therebytransport the work to an accumulation area in the safety cabin.

Accordingly, the feature of double carriages in the safety cabin can befully utilized, and the machined work is carried out to the accumulationarea in the safety cabin, by the holding device provided in the othersecond carriage. As a result, the working environment for the laser beammachining is not impaired, and carrying out of the machined work can beperformed without causing a shift of the machined work on the machiningtable, and also, without the laser beam machining being suspended,thereby enabling improvement in the productivity.

An eighth aspect of the present invention provides the laser beammachining method according to the seventh aspect, wherein, when laserbeam machining is performed on the work on the machining table by thelaser machining head provided in at least one of the first and secondcarriages, after having performed laser beam machining until the workbecomes a condition that it can be picked up, the cut portion of thework is picked up by the holding device provided in the second carriage,the final cut portion of the work is again subjected to laser beammachining by the laser machining head provided in the at least onecarriage, and this machined work is held by the holding device providedin the second carriage to thereby be carried to the accumulation area.

Therefore, since pickup is performed by the holding device provided inthe second carriage, even in the middle of cutting a work by the lasermachining head provided in the first carriage, even if the final outportion is cut thereafter, the machined work can be carried outefficiently by the holding device in the second carriage, withoutcausing a shift of the machined work on the machining table.

A ninth aspect of the present invention provides the laser beammachining method according to the seventh or eighth aspect, wherein themachined work to be carried by the holding device in the second carriageis accumulated in the accumulation area within the safety cabin, andafter a desired number of works have been machined, the accumulatedworks are carried out to the outside through an opening provided on theside of the safety cabin.

Since the machined work is accumulated in the accumulation area in thesafety cabin, the working environment for the laser beam machining isnot impaired. Moreover, since the laser beam machining is not suspended,the productivity is improved. When the accumulated machined works arecarried out, it is necessary to open and close the door in the opening,necessarily from the purpose of the safety cabin. However, this carryingout can be performed during the set-up change, and hence theproductivity is not affected.

A tenth aspect of the present invention provides the laser beammachining method, wherein at least one carriage placed in a safety cabinwith the upper part being released is moved in the back and forthdirection above a machining table, while a laser machining head providedin the carriage is moved in the left and right direction to therebyperform laser beam machining on a work on the machining table, and aholding device in a takeout loader provided above the safety cabin ismoved up and down to hold and lift the machined work on the machiningtable from the release portion on the upper part of the safety cabin, tothereby carry the work to the outside of the safety cabin.

Therefore, it has the similar effect as that in the fifth aspect, andsince carrying out of the work is performed from the release portion onthe upper part of the safety cabin by means of the holding device in thetakeout loader, the working environment for the laser beam machining isnot impaired, and carrying out of the machined work can be performedwithout causing a shift of the machined work on the machining table, andalso, without the laser beam machining being suspended, thereby enablingimprovement in the productivity.

Moreover, it is also effective in the case of using a single carriage,and it is possible to carry out the work to the outside of the safetycabin all at once, without accumulating the works in the safety cabin.In the case of double carriages, it is possible to be involved in othermachining such as laser beam machining, marking or drilling with theother second carriages.

An eleventh aspect of the present invention provides the laser beammachining method according to the seventh to tenth aspects, wherein themachining table is a shuttle table.

Therefore, it has the similar effect as that in the sixth aspect, andthe time for carrying out the machined work to the outside of the safetycabin is reduced, and hence this shuttle table can be effectivelyutilized, without delaying the time for set-up change.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of an embodiment of a laser beam machining systemin accordance with the present invention.

FIG. 2 is an elevation view of an embodiment of a laser beam machiningsystem in accordance with the present invention.

FIG. 3 is a perspective view of another embodiment of a laser beammachining system in accordance with the present invention.

FIG. 4 is a schematic perspective view of a conventional entire laserbeam machining system.

FIG. 5 is a partial perspective view for explaining the operation of aconventional laser beam machining system.

FIG. 6 is a plan view for explaining the operation of a conventionallaser beam machining system.

FIG. 7 is a partial sectional view taken along the line VII—VII in thedirection of an arrow.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the laser beam machining system of the present inventionand the laser beam machining method using this system will be describedwith reference to the drawings.

Referring to FIG. 1 and FIG. 2, a laser beam machine 1 in thisembodiment has a bed 3, and two-stage upper pallet 7 and lower pallet 9constituting, for example, a shuttle table 5 as a machining table isprovided on the bed 3, respectively, so as to be able to movehorizontally and back and forth (right and left, in the X-axis directionin FIG. 1 and FIG. 2).

With the upper pallet 7 and the lower pallet 9, the set-up of a work Won the pallet 7, 9 is performed at area A3, and laser beam machining isperformed on the set work W with the other pallet at Area A1. Forexample, as shown in FIG. 1, the lower pallet 9 is moved to the laserbeam machining area A1, and laser beam machining is performed withrespect to the work W set on the lower pallet 9. The upper pallet 7 ismoved to the outer set-up area A3 away from the laser beam machiningarea A1, to perform setting of the work W on the pallet 7, while laserbeam machining is performed with the lower pallet 9.

Moreover, in FIG. 1 and FIG. 2, a first carriage 11 in a gate shape isprovided on the left side of the bed 3, spanning over rails 13 extendedin the X-axis direction on the both left and right sides (upper andlower sides in FIG. 1) of the bed 3. The first carriage 11 is locatedabove the shuttle table 5, and it can be freely moved and positioned inthe X-axis direction on the rails 13, by a first carriage drive motor(not shown) that is driven under control of a numerical control unit (NCunit).

In the first carriage 11, there is provided a Y-axis carriage 15 movablein the right and left direction (Y-axis direction) orthogonal to theX-axis direction; the carriage 15 can be freely moved and positioned bya Y-axis motor (not shown) driven under control of the NC unit. Morespecifically, a Y-axis ball screw (not shown) rotated and driven by theabove Y-axis motor is extended in the Y-axis direction; the Y-axis ballscrew is born by the first carriage 11. A laser machining head 17 whichcan be freely moved and positioned in the vertical direction (Z-axisdirection) orthogonal to the X- and Y-axis directions is provided belowthe Y-axis carriage 15. The laser machining head 17 can be freely movedand positioned by a Z-axis motor (not shown) driven under control of theNC unit.

Moreover, a nozzle comprising a condenser lens (not shown) for laserbeam machining is fitted at the bottom end of the laser machining head17.

With the above construction, the laser beam emitted from a laseroscillator (not shown) and transmitted to the head 17 via a plurality ofbend mirrors (not shown) is irradiated towards the work W from thenozzle at the bottom of the laser machining head 17. Therefore, when theupper pallet 7 or the lower pallet 9 on which the work W has been set ismoved in the X-axis direction, while the laser machining head 17 ismoved in the Y-axis direction or in the Z-axis direction, thereby laserbeam machining is performed at a desired position of the work W.

In addition, on the right side of the first carriage 11 in FIG. 1 andFIG. 2, a second carriage 19 in a gate shape having substantially thesame structure as that of the first carriage 11 is provided, spanningover the rails 13 on the bed 3, such that it can be freely moved andpositioned in the X-direction on the rails 13 by a second carriage drivemotor (not shown) driven under control of the NC unit.

Moreover, in the second carriage 19, there is provided a Y-axis carriage21 having a similar construction to that of the Y-axis carriage 15 inthe above-described first carriage 11; the carriage 21 is freely movedand positioned in the Y-axis direction. A laser machining head 23 havinga similar construction to that of the laser machining head 17 of theabove-described first carriage 11 is provided below the Y-axis carriage21 so as to be freely moved and positioned in the Z-axis direction.

Laser beam machining by means of the laser machining head 23 in thesecond carriage 19 is the same as that by the first carriage 11described above.

Moreover, on the second carriage 19, a stretch 27 of a holding device 25for holding a work W on the shuttle table 5 is provided on the lowersurface of the Y-axis carriage 21 on the both sides of the lasermachining head 23; the stretch 27 is able to go up and down freely. Thisholding device 25 can be freely moved and positioned by the Z-axis motor(not shown) driven under control of the NC unit. When laser beammachining is performed by the laser machining head 23, the holdingdevice 25 is positioned above a position at the bottom of the lasermachining head 23, and when the work W is held by the holding device 25,the laser machining head 23 is positioned above the position of theholding device 25.

As the holding device 25, a plurality of vacuum pads (not shown) suckedby air vacuum are provided on the bottom face of the stretch 27 that ismoved up and down by, for example, a Z-axis motor for holding device.

In addition, in the second carriage 19, devices such as a marking heador a drilling head may be provided other than the above describedlaser-machining head 23.

Referring to FIG. 1 and FIG. 2, the whole traveling range of the firstcarriage 11 and the second carriage 19 is covered with the safety cabin29. In the safety cabin 29, there are provided a laser beam machiningarea A1 for performing laser beam machining on the work W on the leftside in FIG. 1, and a work accumulation area A2 for accumulating themachined works W (products G in FIG. 1) on the right side.

As shown in FIG. 2, since this work accumulation area A2 is located at alower position than the traveling position of the upper and lowerpallets 7, 9 of the shuttle table 5, there is no problem. Moreover, anopening 31 for taking out the machined works W (products G) accumulatedin the work accumulation area A2 is provided on the side of the safetycabin 29 facing the work accumulation area A2, and a door 33 for openingand closing this opening 31 is also provided.

In the work accumulation area A2, for example, a first conveyor device35 may be arranged as the work transport means, and a second conveyordevice 37 capable of carrying the works W from the first conveyor device35 may be provided outside of the opening 31. In this case, the door 33may be provided at the opening 31, as described above, but an aircurtain may be provided.

Alternatively, a work accumulation pallet may be provided in the workaccumulation area A2. In this case, a forklift or the like may take outworks W.

With the above construction, when one of the upper and lower pallets 7,9 of the shuttle table 5 is located in the laser beam machining area A1,machining of the work W set on the upper pallet 7 or on the lower pallet9 is performed by means of laser beam from one of the laser machininghead 17 or 23 on the first and second carriages 11, 19. In thisembodiment, laser beam machining may be performed by the laser machininghead 17 of the first carriage 11, but laser beam machining may beperformed by both of the first and second carriages 11, 19.

At this time, laser beam machining is performed up to the middle of thecutting length of the work W. That is to say, the work W is cut until acut portion of the work W becomes a condition that it can be picked up.Explaining it by using FIG. 6 and FIG. 7 which have been used forexplaining the conventional system, laser beam machining is suspended,slightly leaving the uncut portion N, as shown in FIG. 6. Then, theholding device 25 of the second carriage 19 (corresponding to referencesymbol 113 in FIG. 6 and FIG. 7) approaches the work W, and the side ofthe cut portion C of the work W in FIG. 6 is picked up by the holdingdevice 25 in the direction of an arrow, as shown in FIG. 7. In FIG. 7,this condition is exaggerated for easy understanding.

Thereafter, the second carriage 19 is retreated, and the remaining uncutportion N is cut by laser beam from the laser machining head 17 of thefirst carriage 11.

After the laser beam machining has been finished, and when the firstcarriage 11 is retreated, the second carriage 19 approaches the work W,and the machined work W is held and lifted by the holding device 25, andcarried and accumulated on, for example, the first conveyor device 35 inthe accumulation area A2.

Meanwhile, laser beam machining is performed on the next work W by thelaser machining head 17 of the first carriage 11, and the abovemachining is repeated.

At the time of unloading the machined works W (products G) accumulatedin the above work accumulation area A2, it is necessary to open or closethe door 33 of the opening 31, in view of the purpose of the safetycabin 29. However, this unloading may be performed during a set-upperiod, such as the period for replacing the upper and lower pallets 7,9 of the shuttle table 5, and does not affect the productivity.

Moreover, by providing an air curtain, works W can be carried outcontinuously, without impairing the working environment in the safetycabin 29.

As described above, a series of steps of the above-described cuttingprocess comprise: (1) performing laser beam machining on a work Whalfway by the laser machining head provided in at least one carriage ofthe first and second carriages 11, 19; (2) picking up the work W by theholding device 25 of the second carriage 19; (3) machining the remainingportion of the work W by the laser machining head disposed in thecarriage; and (4) the machined work W is taken out by the holding device25 of the second carriage 19 and accumulated in the work accumulationarea A2.

Incidentally, the whole tact time required for cutting one work W by thelaser beam machining using the above method was, for example, 17seconds. The breakdown was such that pure laser beam machining time inthe steps (1) and (3) was for example 12 seconds, and the pick-up timeof the work W in other steps (2) and (4) was for example 5 seconds. Inthe conventional method, the whole machining time is for example 30seconds, and hence, the present invention enables great reduction in thetact time.

Moreover, the feature of double carriages can be fully utilized in thesafety cabin 29, such that the holding device 25 disposed in the secondcarriage 19 performs the pickup of the work W in the middle of cuttingthe work W and the unloading of the machined work W (product G). As aresult, the unloading of the machined work can be performed withoutimpairing the working environment for the laser beam machining, withoutthe laser beam machining being suspended, and without causing a shift ofthe machined work on the upper and lower pallets 5, 9, thereby enablinggreat improvement in the productivity.

Next, a laser beam machining method and a laser beam machining system inanother embodiment of the present invention will be described, withreference to the drawings. The laser beam machine 1 in this embodimentis basically the same as the laser beam machine 1 in the above-describedembodiment shown in FIG. 1 and FIG. 2. Therefore, members same as thoseshown in FIG. 1 and FIG. 2 are denoted by the same reference symbols,and only the different points will be described.

Referring to FIG. 3, a safety cabin 39 has an open portion 41 with theupper part is open. Harmful fume due to dust collection during laserbeam machining is reliably drawn downwards, and hence there is no worrythat the working environment is damaged, there may be no upper lid inthe safety cabin 39.

In the safety cabin 39, there are provided two carriages, that is, firstand second carriages 11, 19. A work accumulation area 43 foraccumulating machined works W (product G in FIG. 3) is provided on theright side in FIG. 3 of the shuttle table 5 located in the set-up areaA3 outside the safety cabin 39.

The safety cabin 39 and work accumulation table 43 in FIG. 3, a takeoutloader 47 like an overhead traveling crane is provided; the loader 47has a holding device 45 for holding a work W on one of the upper andlower tables 7, 9 installed in the safety cabin 39.

Specifically, a takeout rail 49 extending substantially horizontally,from the position of the safety cabin 39 to the position rightward inthe X-axis direction in FIG. 3, is arranged in a standing condition. Acantilever-type takeout body 53 of the takeout loader 47 is set up onthe takeout rail 49 so as to be able to reciprocate.

A takeout ball screw (not shown) rotated and driven by a takeout motor(not shown) is born inside of the takeout rail 49, and a nut memberprovided in the takeout body 53 is screwed together with the takeoutball screw. Therefore, the takeout body 53 is reciprocated in the X-axisdirection along the takeout rail 49 by the reciprocal rotation of thetakeout motor.

Moreover, a lift cylinder 57 comprising a piston rod 55 movable in thevertical direction is provided in the takeout body 53, so as to be movedand positioned freely in the Y-axis direction. Plane stretches 59extending in the Y-axis direction are provided at the bottom of thepiston rod 55, and a plurality of vacuum pads (not shown) for holdingthe work W are provided on the bottom face of the stretches 59.

With the above construction, laser beam machining is performed on a workW in the safety cabin 39, in the similar manner as in theabove-described embodiment shown in FIG. 1 and FIG. 2. In the step (2)of the series of steps (1) to (4) in the cutting process, the work W ispicked up by the holding device 45 of the takeout loader 47. Also in thestep (4), after the machined work W has been held and lifted by theholding device 45 of the takeout loader 47, which is moved downwardthrough the open portion 41 of the safety cabin 39, the takeout body 53is moved by means of the rotation of the takeout motor, thereby themachined work W (product G) is carried to and accumulated on the workaccumulation table 43.

The operation and effects in this embodiment are basically the same asthose of the laser beam machine 1 in the embodiment shown in FIG. 1 andFIG. 2 described above. In FIG. 3, the description has been made for acase of double carriages, but it is also effective with the singlecarriage, and it is possible to unload works all at once onto the workaccumulation table 43, without accumulating the works inside of thesafety cabin 39. In the case of double carriages, for example, thesecond carriage 19 can be involved in other machining, such as laserbeam machining, marking or drilling.

The present invention is not limited to the above-described embodiments,and can be executed in other embodiments, by applying appropriatemodifications.

As is understood from the description of the preferred embodimentsdescribed below, according to the first aspect of the invention, thefeature of double carriages in the safety cabin can be fully utilized,and the work is picked up by the holding device provided in the secondcarriage, during cutting the work, and the machined work is carried outto the accumulation area in the safety cabin. As a result, the workingenvironment for the laser beam machining is not impaired, and carryingout of the machined work can be performed without causing a shift of themachined work on the machining table, and also, without the laser beammachining being suspended, thereby enabling improvement in theproductivity.

According to the second aspect of the invention, with the secondcarriage, not only carrying out of the work by means of the holdingdevice, but also other machining can be performed, such as laser beammachining, marking or drilling.

According to the third aspect of the invention, the machined workaccumulated in the safety cabin can be carried out easily and quickly bythe work transport means through the opening. Carrying out is performedduring a set-up change, without affecting the productivity.

According to the fourth aspect of the invention, by providing the freelyopenable door in the opening, laser beam machining can be performedwithout impairing the working environment in the safety cabin. Moreover,by providing the air curtain, continuous carrying out of the work ispossible without impairing the working environment in the safety cabin.

According to the fifth aspect of the invention, since carrying out ofthe work is performed by means of the holding device in the takeoutloader, the working environment for the laser beam machining is notimpaired, and carrying out of the machined work can be performed withoutcausing a shift of the machined work on the machining table, and also,without the laser beam machining being suspended, thereby enablingimprovement in the productivity.

Moreover, it is also effective in the case of using a single carriage,and it is possible to carry out the works to the outside of the safetycabin all at once, without accumulating the works in the safety cabin.In the case of double carriages, it is possible to be involved in othermachining such as laser beam machining, marking or drilling with theother second carriage.

According to the sixth aspect of the invention, the time for carryingout the machined work to the outside of the safety cabin is reduced. Asa result, this shuttle table can be effectively utilized, withoutdelaying the time for set-up change.

According to the seventh aspect of the invention, the feature of doublecarriages in the safety cabin can be fully utilized, and the machinedwork is carried out to the accumulation area in the safety cabin, by theholding device provided in the other second carriage. As a result, theworking environment for the laser beam machining is not impaired, andcarrying out of the machined work can be performed without causing ashift of the machined work on the machining table, and also, without thelaser beam machining being suspended, thereby enabling improvement inthe productivity.

According to the eighth aspect of the invention, since pickup isperformed by the holding device provided in the second carriage in themiddle of cutting a work, even if the final cut portion is cutthereafter, the machined work can be carried out efficiently by theholding device in the second carriage, without causing a shift of themachined work on the machining table.

According to the ninth aspect of the invention, since the machined workis accumulated in the accumulation area in the safety cabin, the workingenvironment for the laser beam machining is not impaired. Moreover,since the laser beam machining is not suspended, the productivity isimproved. Carrying out of the accumulated machined works is performedduring the set-up change, and hence the productivity is not affected.

According to the tenth aspect of the invention, it has the similareffect as that in the fifth aspect, and since carrying out of the workcan be performed by means of the holding device in the takeout loader,the working environment for the laser beam machining is not impaired,and carrying out of the machined work can be performed without causing ashift of the machined work on the machining table, and also, without thelaser beam machining being suspended, thereby enabling improvement inthe productivity.

Moreover, it is also effective in the case of using a single carriage,and it is possible to carry out the works to the outside of the safetycabin all at once, without accumulating the works in the safety cabin.In the case of double carriages, it is possible to be involved in othermachining such as laser beam machining, marking or drilling with theother second carriage.

According to the eleventh aspect of the invention, it has the similareffect as that in the sixth aspect, and the time for carrying out themachined work to the outside of the safety cabin is reduced, and hencethis shuttle table can be effectively utilized, without delaying thetime for set-up change.

1. A laser beam machining system, wherein a machining area and anaccumulation area adjacent to the machining area are provided in asafety cabin; a machining table is disposed in said machining area; andfirst and second carriages disposed on the opposite sides of saidmachining area are provided movably back and forth, located above themachining table; a laser machining head movable in the left and rightdirection is disposed in said first carriage; and a machining headmovable in the left and right direction and a holding device for holdinga work on the machining table are disposed in said second carriage.
 2. Alaser beam machining system according to claim 1, wherein said machininghead in the second carriage comprises at least one of a laser machininghead, a marking head, or a drilling head.
 3. A laser beam machiningsystem according to claim 1, wherein an opening for unloading a work isprovided on the side of said safety cabin, and a work transport meanscapable of unloading a work from inside of the safety cabin to theoutside through said opening is provided in said accumulation area.
 4. Alaser beam machining system according to claim 3, wherein a freelyopenable door or an air curtain is arranged in said opening.
 5. A laserbeam machining system wherein first and second carriages are providedmovably back and forth, located above a machining table in a safetycabin whose upper portion is open, a laser machining head movable rightand left is disposed in at least one of said first and second carriages,and an unloader is provided, which comprises a holding device forholding a work on the machining table from the open portion on the upperpart of said safety cabin, so as to be movable vertically andsubstantially horizontally above said safety cabin.
 6. A laser beammachining system according to claim 1, wherein said machining table is ashuttle table.
 7. A laser beam machining system wherein first and secondcarriages are provided movably back and forth, located above a machiningtablein a safety cabin whose upper portion is open, and an unloader isprovided, which comprises a holding device for holding a work on themachining table from the open portion on the upper part of said safetycabin, so as to be movable vertically and substantially horizontallyabove said safety cabin.